[orca-list] On Firefox: Orca jumps back to the beginning of the page after loading even if the user has already moved on the page

[Alex ARNAUD <alexarnaud hypra fr>]

Hello all,

Environment:
- Debian 9 "Stretch"
- Orca master
- Firefox ESR 60.4 with e10s enabled

1) Open https://www.nextinpact.com/lebrief/edition-232.htm
2) Move the cursor on "En août, le moteur de recherche" (the page is 
loading)
3) Wait until page finish loading
4) Press down arrow

Result:
The caret jumps back to the beginning of the page and down arrow moves 
the caret on the second line

Expected result:
The caret should move on "États-Unis et la France, sans donner plus de 
détails."

I hope Orca could detect the user has manually moves inside the page and 
stops going at the beginning of the page to - I imagine - starts reading 
it when the page finishes to load.

Best regards,
Alex.